Denso Corporation

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Toyota Jidosha Kabushiki Kaisha

Nippondenso Co., Ltd.

Kabushiki Kaisha Toyota Jidoshokki

Denso Corporation Kariya

Hajime Ito

Shinji Aoki

Toshio Morikawa

Yoshiaki Takano

Hikaru Sugi

Satoshi Izawa

Yasushi Kato

Goro Uchida

Yoshimitsu Inoue

Takashi Ban

Norifumi Ban

Takeshi Yoshinori

Takao Tsuruhara

Yasutoshi Suzuki

Yasushi Yamanaka

Yasuaki Makino

Seiichiro Ishio

Yuichi Kajino

Keiichi Shimaoka

Koji Takahashi

Norikazu Ohta

Shunji Mase

Mitsuo Inagaki

Hidefumi Mori

Takahiro Moroi

Hiroyuki Ban

Tatsuyuki Hoshino

Kenichi Ao

Sadahisa Onimaru

Hiroshi Kishita

Takashi Nagasaka

Michiyasu Yamamoto

Nobuaki Hoshino

Mitsuhiro Saitou

Hirofumi Funabashi

Takeshi Wakisaka

Hirohito Matsui

Masashi Takagi

Mikio Fukuoka

Kiyoshi Yamamoto

Mitsugu Nakamura

Masaru Tsunokawa

Hirofumi Funahashi

Toshinao Aoki

Yuji Kutsuna

Mikio Sugiki

Shozo Tatematsu

Toshihiro Oshima

Takao Tsuruhata

Shiniji Aoki

A physical quantity detector includes a pressure-responsive bridge circuit that outputs a detection voltage including a voltage component corresponding to atmospheric pressure and a voltage component corresponding to a change quantity from the atmospheric pressure, a filter that eliminates the voltage component corresponding to the change quantity from the atmospheric pressure, and a variable gain unit that amplifies a voltage difference between the detection voltage outputted from the bridge circuit and the filter output voltage that is free form the change quantity from the atmospheric pressure.

Physical quantity detector

A sensor circuit includes an AC component pickup circuit and first and second adder circuits or first and second high-pass filters, and specifies a range of normal voltages by an upper-limit voltage formed by adding an upper-limit threshold value to the AC component in the input voltage and by a lower-limit voltage formed by adding a lower-limit threshold value to the AC component in the input voltage. An abnormal offset voltage is detected by judging whether the output voltage of an inverting amplifier circuit is lying in the range of normal voltages.

Sensor circuit for detection of an abnormal offset voltage

The electrostatically-driven/capacitance-detection type gyro sensor has a sensing element including a movable part, the sensitivity of the sensing element and accordingly the sensitivity of a sensor output signal thereof being kept unchanged by controlling the amplitude of displacement or displacing velocity of the movable part and by using a reference voltage independent of variation of a power supply voltage, even there occurs a change in the vibrating state of the movable part due to temperature change or secular variation.

Gyro sensor

In an anomaly detector that detects an abnormal condition of an oscillation signal of a circuit such as a vibratory sensing circuit, the oscillation signal, having AC and DC components, is converted to a pair of first and second signals of either opposite-polarity DC amplitudes or opposite-phase alternating amplitudes. The first and second signals are combined to cancel the AC component of the oscillation signal to detect the DC component. The DC component is then compared with the upper and lower thresholds of a decision range to produce an alarm if the DC component goes outside the decision range. In one embodiment, the first and second signals are produced by detecting positive and negative peak values of the oscillation signal at intervals. In a second embodiment, the first signal is produced by high-pass filtering the oscillation signal as a replica of the AC component and the second signal is the oscillation signal itself.

Anomaly detector for vibratory angular rate sensor

In a charge amplifier, an operational amplifier is provided. The operational amplifier has an inverting input terminal, a non-inverting input terminal, and an output terminal. An adjustable feedback resistor element is provide to be connected between the inverting terminal and the output terminal. A resistance adjusting circuit is provided to be electrically connected to the adjustable feedback resistor element. The resistance adjusting circuit adjusts the resistance of the adjustable feedback resistor element to a first resistance during a first predetermined period after power-on. The resistance adjusting circuit also adjusts the resistance of the adjustable feedback resistor element to a second resistance after the first predetermined period has elapsed. The second resistance is higher than the first resistance.

Charge amplifier

A vibratory angular rate sensor comprises a vibrator having a vibrating element arranged to oscillate along a first direction, the element being arranged to further oscillate along a second direction perpendicular to the first direction when subjected to angular rate about a third direction perpendicular to the first and second directions. The vibrating element is caused to oscillate at a predetermined frequency along the first direction. An oscillation detector generates a voltage representing oscillations of the vibrating element along the second direction. A first synchronous detector synchronously detects a primary frequency component of the generated voltage using clock pulses of the predetermined frequency to produce an output signal. A second synchronous detector synchronously detects an odd-numbered harmonic of the generated voltage using clock pulses of the odd-numbered harmonic frequency. A residual odd-numbered harmonic component contained in the output signal of the first synchronous detector is cancelled with the detected odd-numbered harmonic.

Vibratory angular rate sensor

The gyro sensor uses a clock signal as a timing signal or synchronous signal for reading various data stored in a built-in memory for its yaw rate sensing operation. The gyro sensor is configured to use, as such a clock signal, the self-excited oscillation signal being applied to the vibrator of the gyro sensor as a vibrator drive signal.

An angular velocity sensor device includes a switch (S) for selecting a first or second driving signal mutually opposite in phase applied to driving electrodes (D, D) to oscillate a weight part () in a first direction. An adding circuit () adjusts the amplitude of the driving signal selected and adds it to a monitor signal reflecting the oscillating state of the weight part (). A noise signal component appearing in the output signal of the adding circuit () is adjusted to a minimum and the output signal is supplied as a feedback signal to a self-oscillating circuit () for reducing the noise signal influence on the oscillating drive of the weight part.

Angular velocity sensor device

First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.

METHOD OF MEASURING A CHARACTERISTIC OF A CAPACITIVE TYPE OF SENSOR, A SENSOR CHARACTERISTIC MEASURING APPARATUS, A CAPACITIVE TYPE OF SENSOR APPARATUS, AND AN IC CHIP FOR MEASURING A SENSOR CHARACTERISTIC

In a capacitive sensor apparatus, a capacitive sensor includes a plurality of physical-quantity-detection capacitors each having a movable electrode and a fixed electrode. A conversion device operates for converting an output signal of the capacitive sensor into an apparatus output signal. Each of the physical-quantity-detection capacitors is selectively connected and disconnected to and from the conversion device. A determination is made as to whether or not each of the physical-quantity-detection capacitors fails in response to the sensor output signal. When it is determined that a first one of the physical-quantity-detection capacitors fails, the first one is disconnected from the conversion device and a second one of the physical-quantity-detection capacitors is connected to the conversion device.

Capacitive sensor apparatus

A refrigerating cycle apparatus is used in an air-conditioning system of an automotive vehicle, which is capable of operating in a hot gas bypass heating mode. Here, the discharge side of a compressor is directly connected through a hot gas bypass conduit to the inlet side of an evaporator. The evaporator acts as a radiator, heated by gas refrigerant. The compressor is stopped during operation of the apparatus in this heating mode when a physical quantity representing the high-side pressure at the compressor discharge side rises above a set value. The compressor is restarted when a physical quantity representing a heating capacity (for example the high-side pressure) falls below a set value which indicates that there is no heating capacity in the stopped state of the compressor. As a result, the heating capacity obtained through hot gas bypass can be controlled well without frequent stopping and restarting of the compressor.

Refrigerating cycle apparatus

A vehicle air conditioner that inhibits re-evaporation of condensed water on the surface of an evaporator that might fog the inner surface of the vehicle windshield during operation of a hot gas heating cycle heating mode. It is possible to switch operation of a cooling mode by an ordinary refrigerating cycle by opening the inlet side of a condenser and closing the inlet side of a hot gas bypass passage. It is also possible to switch the operation of the heating mode by closing the inlet side of the condenser and opening the inlet side of the hot gas bypass passage. When it is determined during operation of the heating mode that the windshield will fog, operation of the air conditioning compressor is interrupted by the air conditioning control unit so that the temperature of an evaporator reaches no more than a predetermined value.

Vehicle air conditioner with windshield anti-fog feature

In a refrigerant cycle system, a refrigerant discharge side of a compressor is directly connected to a refrigerant inlet side of an evaporator through a hot-gas bypass passage so that the evaporator is used as a radiator during a heating mode due to the hot-gas bypass. A physical amount of refrigerant, such as a high-pressure side refrigerant pressure, flowing through the hot-gas bypass passage is detected. When the high-pressure side refrigerant pressure is decreased to a value corresponding to a refrigerant shortage area, a refrigerant shortage is determined and the compressor is stopped by a control unit. Thus, during the heating mode due to the hot-gas bypass, when a refrigerant leakage is caused in the refrigerant cycle system, the compressor is accurately protected.

Refrigerant cycle system having hot-gas bypass structure

A heating apparatus for a vehicle includes a pump for circulating cooling water in a cooling water circuit, a heating heat exchanger for heating air blown into a passenger compartment of the vehicle using cooling water as a heating source, and a throttle valve disposed at a discharge side of the pump. In the heating apparatus, when the temperature of cooling water is low and heating capacity for heating the passenger compartment is insufficient, an opening degree of the throttle valve is reduced by a control unit. Therefore, heat is generated from the throttle valve and the pump so that the temperature of cooling water is increased. Thus, heating capacity of the heating apparatus can be improved without using a manual operation.

Heating apparatus for vehicle

A refrigeration cycle for a vehicle air conditioner has a bypass passage between a compressor and an evaporator. In a heating mode, high-temperature gas refrigerant discharged from the compressor is directly introduced into the evaporator through the bypass passage while bypassing a condenser to improve a heating performance of the air conditioner. When a refrigerant recovery mode in which refrigerant staying in the condenser is forced to be discharged and introduced into the evaporator is set, a passage between the condenser and the evaporator in which a thermostatic expansion valve is disposed is controlled to be opened a predetermined amount. As a result, refrigerant staying in the condenser is securely returned to the evaporator even when a temperature of outside air is extremely low and the expansion valve is closed.

Refrigeration cycle for vehicle air conditioner

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Kariya, Japan

Hajime Ito